Project Blackbox by Sun is certainly a fascinating concept. The infrastructure needs are significant, and what would be truly awesome is if they came up with a standardized set of quick-release power and cooling couplers. That would make this a truly useful piece of technology. Nicholas Carr's comments regarding the utilitization of electricity and its applicability to computing are quite correct.
You can always read the NY Times take on it, but I doubt the link will work for very long and I'm always disappointed in the quality of the reporting when I read a times article about something I do know about.
Photo from Aaron Cohen's blog.